This application claims priority under 35 U.S.C. §109(a) on Patent Application No. 2009-235968 filed in Japan on Oct. 13, 2009, the entire contents of which are herein incorporated by reference.
The present invention relates to image forming apparatuses such as copiers, printers, and fax machines.
Electrophotographic apparatuses are an example of this type of image forming apparatus. In electrophotographic apparatuses, a toner image is formed on a surface of a photosensitive drum by forming an electrostatic latent image on the surface of the photosensitive drum, then developing the electrostatic latent image on the surface of the photosensitive drum using toner, and the toner image is transferred from the photosensitive drum to a recording paper and fixed onto the recording paper by applying heat and pressure to the recording paper.
Image forming apparatuses such as these are essential office automation appliances and are installed in most offices, moreover they are also becoming widespread in homes and hospitals.
In this regard, electrophotographic image forming apparatuses have sometimes caused discomfort to many people in offices, homes, and hospitals and the like since they produce exhaust gases and the like during the process of forming a toner image on the recording paper.
For this reason, in JP 2005-4144A for example, components such as a ventilation fan, a negative ion generating portion, a positively charged filter, and an ozone filter are provided inside an image forming apparatus, and while the inside of the image forming apparatus is ventilated by the ventilation fan, dust and mold and the like that have entered from outside are negatively charged by the negative ion generating portion and these are adsorbed and removed by the positively charged filter, or gases or the like inside the image forming apparatus are reduced by an ozone removal filter, thereby discharging clean air to the outside. Accordingly, with the conventional technology of JP 2005-4144A, it is possible to remove dust and mold and the like that have entered from outside the image forming apparatus, and to reduce gases inside the image forming apparatus to release clean air externally.
However, with the conventional technology of JP 2005-4144A, despite being able to purify the air in a room, the negative ion generating portion is a structure that is exposed to gases inside the image forming apparatus, and therefore the ion generating efficiency of the negative ion generating portion is reduced at an early stage. This is considered to be because the gases inside the image forming apparatus contain silicone that is mixed with toner powder and release agents for releasing recording papers, and this silicone adheres to components such as the discharging electrodes of the negative ion generating portion, which reduces the insulation of the negative ion generating portion.
Accordingly, the present invention was devised to address the above-described issues, and it is an object thereof to provide an image forming apparatus that has an inbuilt air purifier having an ion generator, and that is capable of maintaining the ion generating efficiency of its ion generator without reductions over a long period while purifying the air in a room.